Re: [PATCH 1/3] KVM: nVMX: Fix virtual interrupt delivery injection

Paolo Bonzini
2014-07-17T09:00:47Z

Il 17/07/2014 06:56, Wanpeng Li ha scritto:
> This patch fix bug reported in https://bugzilla.kernel.org/show_bug.cgi?id=73331,
> after the patch http://www.spinics.net/lists/kvm/msg105230.html applied, there is
> some progress and the L2 can boot up, however, slowly. The original idea of this
> fix vid injection patch is from "Zhang, Yang Z" <yang.z.zhang@intel.com>.
>
> Interrupt which delivered by vid should be injected to L1 by L0 if current is in
> L1, or should be injected to L2 by L0 through the old injection way if L1 doesn't
> have set VM_EXIT_ACK_INTR_ON_EXIT. The current logic doen't consider these cases.
> This patch fix it by vid intr to L1 if current is L1 or L2 through old injection
> way if L1 doen't have VM_EXIT_ACK_INTR_ON_EXIT set.
>
> Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
> Signed-off-by: "Zhang, Yang Z" <yang.z.zhang@intel.com>
> ---
> arch/x86/kvm/vmx.c | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 021d84a..ad36646 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -7112,8 +7112,22 @@ static void vmx_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr)
> {
> if (max_irr == -1)
> return;
> -
> - vmx_set_rvi(max_irr);
> + if (!is_guest_mode(vcpu)) {
> + vmx_set_rvi(max_irr);
> + } else if (is_guest_mode(vcpu) && !nested_exit_on_intr(vcpu)) {
> + /*
> + * Fall back to old way to inject the interrupt since there
> + * is no vAPIC-v for L2.
> + */
> + if (vcpu->arch.exception.pending ||
> + vcpu->arch.nmi_injected ||
> + vcpu->arch.interrupt.pending)
> + return;
> + else if (vmx_interrupt_allowed(vcpu)) {
> + kvm_queue_interrupt(vcpu, max_irr, false);
> + vmx_inject_irq(vcpu);
> + }
> + }
> }
>
> static void vmx_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
>

What hypervisor did you test with? nested_exit_on_intr(vcpu) will return
true for both Xen and KVM (nested_exit_on_intr is not the same thing as
ACK_INTR_ON_EXIT).

Paolo